Serve a trusted holder from a runtime of its own account, refuse it in the machine's runtime, and say while an agent can become root where it runs (hq ADR 0259 §8)

internal/catalogue/runtime.go

@@ -170,6 +170,10 @@ func (r Resolution) runtimeProcess(with Rendering) (map[string]any, error) {
 		if with.Adopted && m.Filtering != nil {
 			continue
 		}
+		if m.RunsAs != "" {
+			// Served by a runtime of its own, on its own account (ownRuntimes): never the machine's.
+			continue
+		}
 		words, err := bundleWords(m, with)
 		if err != nil {
 			return nil, err
@@ -232,6 +236,84 @@ func (r Resolution) runtimeProcess(with Rendering) (map[string]any, error) {
 	return process, nil
 }
 
+// OwnRuntimeID names the process a module of its own account is served by (novox/hq ADR 0259 §8).
+func OwnRuntimeID() string { return "own-runtime" }
+
+// ownRuntimes are the processes the modules of their own account are served by (novox/hq ADR 0259 §8): each
+// the machine's runtime program — the same build, run from the same source — serving that one module alone,
+// as the module's own account, on the module's own bus credential. Never the machine's runtime, which runs
+// as the operator's account and carries every module on the machine.
+func (r Resolution) ownRuntimes(with Rendering) ([]map[string]any, error) {
+	var own []Manifest
+	for _, m := range r.Modules {
+		if m.RunsAs != "" && !(with.Adopted && m.Filtering != nil) {
+			own = append(own, m)
+		}
+	}
+	if len(own) == 0 {
+		return nil, nil
+	}
+	var runtime *Manifest
+	for i := range r.Modules {
+		if r.Modules[i].Module == RuntimeModule {
+			runtime = &r.Modules[i]
+		}
+	}
+	if runtime == nil || len(runtime.Bundles) != 1 || runtime.Bundles[0].Binary == "" {
+		return nil, fmt.Errorf("%s runs as its own account in a runtime of its own, and %s is not here to run it "+
+			"from: assign %s to %s first (novox/hq ADR 0259)", own[0].Module, RuntimeModule, RuntimeModule, r.Node)
+	}
+	program := runtime.Bundles[0]
+	var out []map[string]any
+	for _, m := range own {
+		credential, declared := m.OwnSecrets["broker"]
+		if !declared {
+			return nil, fmt.Errorf("%s runs as its own account and declares no own secret broker", m.Module)
+		}
+		var served, restartOn []string
+		for _, b := range m.Bundles {
+			for _, load := range b.Loads {
+				if launcher, has := b.Launchers[load]; has {
+					load = launcher
+				}
+				served = append(served, m.Module+"="+BundlePath(m.Module, b.Name)+"/"+load)
+			}
+			if len(b.Loads) > 0 {
+				restartOn = append(restartOn, m.Module+"."+BundleID(b.Name))
+			}
+		}
+		if len(served) == 0 {
+			return nil, fmt.Errorf("%s runs as its own account and its build produced no bundle to serve", m.Module)
+		}
+		sort.Strings(served)
+		restartOn = append(restartOn, m.Module+"."+NeedID("broker"))
+		sort.Strings(restartOn)
+		env := map[string]string{RuntimeToolModules: strings.Join(served, ","), RuntimeBrokerFile: credential.Path}
+		words, err := bundleWords(m, with)
+		if err != nil {
+			return nil, err
+		}
+		if len(words) > 0 {
+			body, err := json.Marshal(map[string]map[string]string{m.Module: words})
+			if err != nil {
+				return nil, err
+			}
+			env[RuntimeToolEnv] = string(body)
+		}
+		process := map[string]any{
+			"id": m.Module + "." + OwnRuntimeID(), "type": "process", "name": m.Module + "-runtime",
+			"source": program.Source, "digest": program.Digest,
+			"run": []any{"./" + program.Binary}, "env": env, "restart-on": toAny(restartOn),
+			"user": m.RunsAs,
+		}
+		if err := artifactsInto(process, RuntimeModule, with); err != nil {
+			return nil, err
+		}
+		out = append(out, process)
+	}
+	return out, nil
+}
+
 func toAny(in []string) []any {
 	out := make([]any, 0, len(in))
 	for _, s := range in {